Bag valve



Oct. 31, 1950 E. E. BURROUGHS BAG VALVE Filed July 30, 1948 INVENTOR.

EDWIN E. Bu R RoucsHs. BY

ATTORNEYS.

Patented Oct. 31, 1950 BAG VALVE Edwin E. Burroughs, Brooklyn,- N. Y.,assignor to St. Regis Paper Company, New York, N. Y., a

corporation of New York Application July 30, 1948, Serial No. 41,480

4 Claims.

This invention relates to valve bags. such as formed for example, of oneor more plies of paper or the like sheet material.

The features of the invention comprise improvments upon andmodifications of the general type of bag valve disclosed in UnitedStates Patent to Theron A. Contryman, No. 2,378,285, granted June 12,1945. According to the disclosure of said patent one of the corners of amulti-ply gusseted paper bag is folded in to form a valve and the end ofthe bag is closed by a sewn seam. In order to provide a more efiectiveclosing action in the valve when the bag is filled, a supplemental sheetis inserted so as to provide a flexible extended valve flap protrudinginwardly from the inner edge of the main multiply valve flap. When thebag is empty this supplemental sheet is so folded and creased as to formin effect a flattened tube extending inwardly of the bag, and the creasealong the lower edge thereof is slitted at least part-way. Additionalslits are also provided in the inner edge of the supplemental sheet atpositions intermediate the upper and lower edge thereof and along thelines at which the supplemental sheet becomes folded when the bag isexpanded and filled and when the contents of the bag crowd thesupplemental sheet, from its original vertically fiatwise position, intoa position flatwise up against the top of the bag to effectively closethe valve. In the latter position the slit formed along the lowercreased edge of the supplemental sheet is such that overlapping of thetwo sides of the supplemental sheet is facilitated thus avoidingirregular crushing of the extension flap with consequent incompleteclosure of the valve. At the same time, the two slits in the sides ofthe supplemental sheet serve to define the lines of creasing of theextension fiap at its sides when it is pushed up by the contents of thebag into closing position.

In order to facilitate the overlapping of the two edges of paper alongthe slit at which is normally the bottom edge of the folded supplementalsheet, it is desirable to form this slit of substantial width, as byforming a relatively wide saw cut or by cutting out a narrow piece asexplained in said patent. This. however, has the difficulty that smallpieces or narrow strips of the paper will be out free and may find theirway into the bag contents or into the mechanism used for automaticallyvalving or sewing the bag or inserting the supplemental sheet therein.Also the slit edges may sometimes as- 2 sume position crossing eachother so that they do not overlap properly.

To avoid these difliculties, in accordance with the present invention,the lower edge of the supplemental sheet or flap extension is formedwith a novel type of slit having advantages superior to those of a wideslit but so formed that the 'paper is merely severed without cutting outany loose pieces. Adjacent the point where the supplemental sheet issecured to the main valve fiap the slit preferably veers off in a slightcurve or at any angle whereby the slit terminates at a point a slightdistance above the lower crease line of the supplemental sheet. Fromthis point of termination of the slit, one side of the supplementalsheet, is creased along a line spaced slightly above the slit so thatthe lower edge of one side of the supplemental sheet is bent away fromthe lower edge of the other side. With such a construction it has beenfound that such edges will more readily assume the desired smoothly andclosely overlapped positions when the bag is filled. Thus, a morecertain closure of the valve is made possible without the necessity ofresorting to relatively wide slits and the consequent troublesome loosepieces.

Various further and more specific objects, features and advantages willmore clearly appear from the detaileddescription given below taken inconnection with the accompanying drawings which form a part of thisspecification and illustrate merely by way of example, preferred formsof the invention. The invention consists in such novel features, andcombinations as may be shown and described in connection with theconstruction herein disclosed.

In the drawings:

Figure 1 is a side elevational view partly broken away showing the valvecorner portion of a multi-ply gusseted sewn end bag embodying oneexample of the invention.

Fig. 2 is a perspective view of the corner portion of the same bag inpartially opened condition, after the supplemental sheet or valveextension has been inserted and before the end of the bag has been sewn;

Fig. 3 is a sectional view showing the positions assumed by portions ofthe valve extension flap as the bag becomes filled, this view beingtaken along a line corresponding to that indicated at line 3-3 of Fig.1.

Figure 4 is a plan view of one form of supplemental sheet or extensionflap made in accordance with the invention; and

Figs. 5 to 8, inclusive, show alternative forms.

The bag In as shown in Fig. 1 may be formed of one or preferably aplurality of plies of paper or like sheet material. The walls of the bagmay be manufactured in the usual way in the form of flattened tubessuitably creased at each side to form gusset portions as at H. Incutting the tubes into bag lengths, the line of severance as it extendsacross the greater part of the width of the bag will occur at the topedge as indicated at I2, I? in Fig. 2. However, at the valve corner, ifdesired, the tubes may be severed in such a way as to provide anextension portion or so-called "notch which after the valve corner hasbeen folded in as at I3, will provide a flap portion as at M which willextend inwardly of the valve somewhat beyond the points l5, l5 where thediagonal fold lines l6, [6' of the valve intersect the lines ofseverance I2, II.

It will be noted that the in-turned corner of the bag which forms thevalve portion l3 will normally have two side walls joined at the bottomalong a crease l8. A supplemental sheet I] for providing the flexibleextension flap, similarly has two side walls Ha, IIb, which are alsoJoined at l8 along the same crease. The edges l9, I! of the supplementalsheet which are directed outwardly of the valve are preferably arrangedto underlie the main flap or notch" portion H of the valve and, ifdesired, may be secured thereto by adhesive in a manner hereinafterdescribed.

As best shown in Fig. 2, the supplemental sheet I! is slit along a linewhich comprises a continuation of the crease line I8, such slitextending preferably all the way from the inner edge 2| of thesupplemental sheet back to approximately the edge 22 of the main flapportion M. This slit 20 at its inner end preferably terminates in ashort angularly directed slit which may be positioned, for example, asshown at 23 in Fig 1 at a right angle with respect to the main slit 20,or if preferred, as shown in Fig. 4, the main slit as at 20a mayterminate in'a portion as at 20bwhich veers off along a short arc.Alternatively, as shown in Fig. 5, the main slit as at 200, mayterminate in a portion as at 20d positioned at an angle, for example, 45with respect to the slit portion 200. With all of these forms, thesupplemental sheet is preferably creased along a line as at 25 (Figs. 4,5) extending in generally parallel relation to the main slit andsomewhat spaced therefrom so as to form a narrow flap-like portion as at26 which is deflected preferably inwardly of the bag.

The side walls Ila and Nb of the flexible extension fiap may also beslitted as at 30a, 3011 along lines positioned about midway between theupper and lower edges of the extension flap, that is, along the lines atwhich the extension flap will be creased when it is flattened up againstthe top of the bag as the bag is being filled and as the pressure of thecontents changes the extension flap from a vertically flat-wise shape,to the shape shown approximately in Fig. 3, wherein the inner upper endportion of a filling spout is indicated in section at 3|. As will beseen from Fig. 3, when the extension flap is in this position, the edgesof the paper at each side of the slit 20 will assume overlappingpositions as indicated at 32 and in the usual case, the narrowdownwardly bent flap portion 25 will protrude inwardly of the bag andbecause of its being flexed downwardly, it will slide past the otheredge of the paper at the slit 20 without catching thereon or causingwrinkling which would prevent proper closing action.

The supplemental sheet may be inserted by hand when the valve parts ofthe bag are partially opened to the position shown in Fig. 2 or, ifdesired, mechanism which forms no part of the present invention may beprovided for automatically performing this operation.

As above indicated, the part of the supplemental sheet which underliesthe main valve flap portion 14 is preferably secured by adhesive to thelatter. Preferably, such adhesive may be initially applied to thesupplemental sheet in the form of a series of small spaced areas asindicated at 33 (Figs. 1 and 2). These spots of adhesive may be applied,for example, by automatic means during or as part of the operation ofcutting the extension flap piece to the desired shape. The use of aseries of separate spots of the adhesive in this way has the advantagethat the number of spots thus automatically applied may be readilyvaried depending upon the dimensions of the particular supplementalsheet being used. That is, a number of the spots may be used such aswill provide secure adhesion at spaced intervals but without anyadhesive occurring at the top edges of the supplemental sheet where theglue (if it were in the form of a continuous band) might smear andinterfere with convenient cutting of the sheet or its assembly andsecurement in place in the valve of the bag.

After the supplemental sheet I! is in place as shown in Fig. 2, the topedges of the bag may be brought together and a reinforcing strip 35formed, for example, of creped paper of U- shaped cross section, may beplaced astride the top edge whereupon the top edge may be closed by asewn seam 35. From Fig. 1 it will be apparent that the stitches of thisseam will pass through the top edges of the supplemental sheet l'Ithereby providing a strengthened construction along the top corner ofthe bag where the weight of the bag may rest upon a filling spout wheninserted into the valve. Also, it will be apparent that this sewn seamacts to securely retain the supplemental sheet in position free ofirregular wrinkles when the bag is filled.

With the alternative form of the invention shown in Fig. 6, an extensionflap 31 is slitted at 38 along a line comparable to the line of the slit:0 in Fig. 1. This slit at its inner end is terminated by a shorttransverse slit 39 extending to either side of slit 38. Then the paperis creased along two lines, 40 and 4|, at either side of and spaced fromslit 38 so as to form two narrow flaps 42 and 43, one of which may bebent upwardly and the other downwardly. With this construction, theedges of the narrow flaps 42 and 43 being bent in opposite directionswill be initially spaced a sufficient distance apart so that furtherinsurance is given against the possibility 'of the two edges coming intoengagement during the final closing operations. Of course, if preferred,instead of using a short straight slit as at 39, slits to either side asat no and 20d in Figs. 4 and 5 might be used.

Further embodiments with which certain advantages of the invention maybe obtained are indicated in Figs. '7 and 8, wherein the shorttransverse slitting is avoided. That is, in Fig. 7 two of the narrowflaps are provided as at 50, 5| by creasing the paper at the side of thecentral slit 52, along slightly diagonal lines as at 53, 54. In Fig. 8 asingle narrow flap is provided at 55 by forming the central slit 56along a slight arc and by forming the line 51 at a slight angle withrespect to the crease line l8 of the valve.

This application comprises a continuation-inpart of applicant'scopending application Serial No. 650,775, filed February 28, 1946, nowabandoned.

While the invention has been described with respect to certainparticular preferred examples which give satisfactory results, it willbe understood by those skilled in the art after understanding theinvention, that various changes and modifications may be made withoutdeparting from the spirit and scope of the invention and it isintendedtherefore in the appended claims to cover all such changes andmodifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. A bag formed of thin sheet material, comprising a normally flattenedtubular body portion with a corner turned in to form a valve, and havinga supplemental sheet extending inward from said inturned corner to forma flexible valve extension flap, said sheet being normally folded alonga crease line which com stitutes the lower edge of the valve flap whenthe bag is empty, the sheet being slit substantially along the line ofsuch crease from the inner edge of the extension back for a substantialdistance toward the outside of the valve, the slit then veering oil? fora short distance to one side of the line of such crease, said flexibleextension flap at said side of said slit being also formed with a creaseline extending generally parallel to the main portion oi said slit andspaced a short distance therefrom, whereby such side of'the extensionflap along its lower edge is deflected from the plane of the adjacentpart of the flap and whereby when the extension flap portions areflattened toward the top of the bag upon filling of the bag, the edgesof the material along the opposite sides of said slit will slide intooverlapping relation.

2, A bag formed of thin sheet material, comprising a normally flattenedtubular b dy portion with a corner turned in to form a valve, and

having a supplemental sheet extgndingjnward from said inturned corner toform flexible valve extension flap, said sheet being normally foldedalong a crease line which constitutes the lower edge of the valve flapwhen the bag is empty, the sheet being slit substantially along the lineof such crease from the inner edge of the extension back for asubstantial distance toward the outside of the valve, said slit thenterminating in a short cut or cuts extending to either side thereof,said flexible extension flap at either side of said slit being formedwith crease lines extending generally parallel to and spaced a shortdistance from said slit .to form narrow flap portions, one of which isdeflected upwardly and the other downwardly, whereby when the extensionflap portions are flattened toward the top 01' the bag upon fllling thebag, the edges of the material along the opposite sides of said 05 witha corner turned in to form a valve flap centrally creased to form itsnormally lower edge, a sewed seam extending along and securing togetherin closed relationship the top edges of the bag and acting also tosecure together the top edges of said valve flap, and a supplementalsheet folded to form in eiIect a flattened sleeve within the valve andextending inwardly thereof to form a flexible valve extension, the edgesof the sheet forming the upper edge of the flattened sleeve beingsecured by said sewed seam and the fold line which constitutes the loweredge of said flattened sleeve being substantially in alignment with thelower creased edge of the valve flap, said sleeve being slitsubstantially along its lower edge from the inner end of the sleeve backfor a substantial distance toward the outside of the valve to a slitextremity intermediate the inner and outer ends of the sleeve, thematerial of the sleeve at one side of said slit being creased to form anarrow flap portion deflected from the plane of the remainder of thesleeve along a line extending from said slit extremity to the inner endof the sleeve at a point spaced a short distance from the slit, wherebywhen the sleeve is flattened toward the top of the bag when the latteris filled, the edges of the material along the opposite sides of saidslit will be slightly spaced apart and will thus freely slide intooverlapping relation.

4. A bag formed 01 thin sheet material, comprising a normally flattenedtubular body portion with a corner turned in. to form a valve, andhaving a supplemental sheet extending inward from said intumed corner toform a flexible valve extension flap, said sheet being normally foldedalong a crease line which constitutes the lower edge of the valveextension flap when the bag is empty, the sheet being slit substantiallyalong the line of such crease from the inner edge of the extension flapback for a substantial distance toward the outside or the valve to aninner terminal point of the slit, said flexible extension flap along atleast one side of said slit also being formed with a crease lineextending from the inner terminal point of the slit and slightlyangularly to the main portion of said slit to the inner edge of theextension flap whereby a portion of the extension flap having saidcrease is deflected from the plane of the adjacent part of the flap, andwhereby when the extension flap portions are flattened toward the top ofthe bag upon the filling oi the bag, the edges of the material of theextension flap along opposite sides of the slit will slide intooverlapping relation.

E'DWIN E. BUR-ROUGHS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,503,516 Porter Aug. 5, 19242,040,336 Rosmait May 12, 1936 2,378,285 Contryman June 12, 19452,418,975 Johnson Apr. 15, 1947

